PuSHSubscriber.php in Feeds 8.2
Pubsubhubbub subscriber library.
Readme http://github.com/lxbarth/PuSHSubscriber
License http://github.com/lxbarth/PuSHSubscriber/blob/master/LICENSE.txt
Namespace
Drupal\feedsFile
lib/Drupal/feeds/PuSHSubscriber.phpView source
<?php
/**
* @file
* Pubsubhubbub subscriber library.
*
* Readme
* http://github.com/lxbarth/PuSHSubscriber
*
* License
* http://github.com/lxbarth/PuSHSubscriber/blob/master/LICENSE.txt
*/
namespace Drupal\feeds;
/**
* PubSubHubbub subscriber.
*/
class PuSHSubscriber {
protected $domain;
protected $subscriber_id;
protected $subscription_class;
protected $env;
/**
* Singleton.
*
* PuSHSubscriber identifies a unique subscription by a domain and a numeric
* id. The numeric id is assumed to e unique in its domain.
*
* @param $domain
* A string that identifies the domain in which $subscriber_id is unique.
* @param $subscriber_id
* A numeric subscriber id.
* @param $subscription_class
* The class to use for handling subscriptions. Class MUST implement
* PuSHSubscriberSubscriptionInterface
* @param PuSHSubscriberEnvironmentInterface $env
* Environmental object for messaging and logging.
*/
public static function instance($domain, $subscriber_id, $subscription_class, PuSHSubscriberEnvironmentInterface $env) {
static $subscribers;
if (!isset($subscriber[$domain][$subscriber_id])) {
$subscriber = new PuSHSubscriber($domain, $subscriber_id, $subscription_class, $env);
}
return $subscriber;
}
/**
* Protect constructor.
*/
protected function __construct($domain, $subscriber_id, $subscription_class, PuSHSubscriberEnvironmentInterface $env) {
$this->domain = $domain;
$this->subscriber_id = $subscriber_id;
$this->subscription_class = $subscription_class;
$this->env = $env;
}
/**
* Subscribe to a given URL. Attempt to retrieve 'hub' and 'self' links from
* document at $url and issue a subscription request to the hub.
*
* @param $url
* The URL of the feed to subscribe to.
* @param $callback_url
* The full URL that hub should invoke for subscription verification or for
* notifications.
* @param $hub
* The URL of a hub. If given overrides the hub URL found in the document
* at $url.
*/
public function subscribe($url, $callback_url, $hub = '') {
// Fetch document, find rel=hub and rel=self.
// If present, issue subscription request.
$request = curl_init($url);
curl_setopt($request, CURLOPT_FOLLOWLOCATION, TRUE);
curl_setopt($request, CURLOPT_RETURNTRANSFER, TRUE);
$data = curl_exec($request);
if (curl_getinfo($request, CURLINFO_HTTP_CODE) == 200) {
try {
$xml = @new SimpleXMLElement($data);
$xml
->registerXPathNamespace('atom', 'http://www.w3.org/2005/Atom');
if (empty($hub) && ($hub = @current($xml
->xpath("//atom:link[attribute::rel='hub']")))) {
$hub = (string) $hub
->attributes()->href;
}
if ($self = @current($xml
->xpath("//atom:link[attribute::rel='self']"))) {
$self = (string) $self
->attributes()->href;
}
} catch (Exception $e) {
// Do nothing.
}
}
curl_close($request);
// Fall back to $url if $self is not given.
if (!$self) {
$self = $url;
}
if (!empty($hub) && !empty($self)) {
$this
->request($hub, $self, 'subscribe', $callback_url);
}
}
/**
* @todo Unsubscribe from a hub.
* @todo Make sure we unsubscribe with the correct topic URL as it can differ
* from the initial subscription URL.
*
* @param $topic_url
* The URL of the topic to unsubscribe from.
* @param $callback_url
* The callback to unsubscribe.
*/
public function unsubscribe($topic_url, $callback_url) {
if ($sub = $this
->subscription()) {
$this
->request($sub->hub, $sub->topic, 'unsubscribe', $callback_url);
$sub
->delete();
}
}
/**
* Request handler for subscription callbacks.
*/
public function handleRequest($callback) {
if (isset($_GET['hub_challenge'])) {
$this
->verifyRequest();
}
else {
if ($raw = $this
->receive()) {
$callback($raw, $this->domain, $this->subscriber_id);
}
}
}
/**
* Receive a notification.
*
* @param $ignore_signature
* If FALSE, only accept payload if there is a signature present and the
* signature matches the payload. Warning: setting to TRUE results in
* unsafe behavior.
*
* @return
* An XML string that is the payload of the notification if valid, FALSE
* otherwise.
*/
public function receive($ignore_signature = FALSE) {
/**
* Verification steps:
*
* 1) Verify that this is indeed a POST reuest.
* 2) Verify that posted string is XML.
* 3) Per default verify sender of message by checking the message's
* signature against the shared secret.
*/
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$raw = file_get_contents('php://input');
if (@simplexml_load_string($raw)) {
if ($ignore_signature) {
return $raw;
}
if (isset($_SERVER['HTTP_X_HUB_SIGNATURE']) && ($sub = $this
->subscription())) {
$result = array();
parse_str($_SERVER['HTTP_X_HUB_SIGNATURE'], $result);
if (isset($result['sha1']) && $result['sha1'] == hash_hmac('sha1', $raw, $sub->secret)) {
return $raw;
}
else {
$this
->log('Could not verify signature.', 'error');
}
}
else {
$this
->log('No signature present.', 'error');
}
}
}
return FALSE;
}
/**
* Verify a request. After a hub has received a subscribe or unsubscribe
* request (see PuSHSubscriber::request()) it sends back a challenge verifying
* that an action indeed was requested ($_GET['hub_challenge']). This
* method handles the challenge.
*/
public function verifyRequest() {
if (isset($_GET['hub_challenge'])) {
/**
* If a subscription is present, compare the verify token. If the token
* matches, set the status on the subscription record and confirm
* positive.
*
* If we cannot find a matching subscription and the hub checks on
* 'unsubscribe' confirm positive.
*
* In all other cases confirm negative.
*/
if ($sub = $this
->subscription()) {
if ($_GET['hub_verify_token'] == $sub->post_fields['hub.verify_token']) {
if ($_GET['hub_mode'] == 'subscribe' && $sub->status == 'subscribe') {
$sub->status = 'subscribed';
$sub->post_fields = array();
$sub
->save();
$this
->log('Verified "subscribe" request.');
$verify = TRUE;
}
elseif ($_GET['hub_mode'] == 'unsubscribe' && $sub->status == 'unsubscribe') {
$sub->status = 'unsubscribed';
$sub->post_fields = array();
$sub
->save();
$this
->log('Verified "unsubscribe" request.');
$verify = TRUE;
}
}
}
elseif ($_GET['hub_mode'] == 'unsubscribe') {
$this
->log('Verified "unsubscribe" request.');
$verify = TRUE;
}
if ($verify) {
header('HTTP/1.1 200 "Found"', NULL, 200);
print $_GET['hub_challenge'];
drupal_exit();
}
}
header('HTTP/1.1 404 "Not Found"', NULL, 404);
$this
->log('Could not verify subscription.', 'error');
drupal_exit();
}
/**
* Issue a subscribe or unsubcribe request to a PubsubHubbub hub.
*
* @param $hub
* The URL of the hub's subscription endpoint.
* @param $topic
* The topic URL of the feed to subscribe to.
* @param $mode
* 'subscribe' or 'unsubscribe'.
* @param $callback_url
* The subscriber's notifications callback URL.
*
* Compare to http://pubsubhubbub.googlecode.com/svn/trunk/pubsubhubbub-core-0.2.html#anchor5
*
* @todo Make concurrency safe.
*/
protected function request($hub, $topic, $mode, $callback_url) {
$secret = hash('sha1', uniqid(rand(), TRUE));
$post_fields = array(
'hub.callback' => $callback_url,
'hub.mode' => $mode,
'hub.topic' => $topic,
'hub.verify' => 'sync',
'hub.lease_seconds' => '',
// Permanent subscription.
'hub.secret' => $secret,
'hub.verify_token' => md5(session_id() . rand()),
);
$sub = new $this->subscription_class($this->domain, $this->subscriber_id, $hub, $topic, $secret, $mode, $post_fields);
$sub
->save();
// Issue subscription request.
$request = curl_init($hub);
curl_setopt($request, CURLOPT_POST, TRUE);
curl_setopt($request, CURLOPT_POSTFIELDS, $post_fields);
curl_setopt($request, CURLOPT_RETURNTRANSFER, TRUE);
curl_exec($request);
$code = curl_getinfo($request, CURLINFO_HTTP_CODE);
if (in_array($code, array(
202,
204,
))) {
$this
->log("Positive response to \"{$mode}\" request ({$code}).");
}
else {
$sub->status = $mode . ' failed';
$sub
->save();
$this
->log("Error issuing \"{$mode}\" request to {$hub} ({$code}).", 'error');
}
curl_close($request);
}
/**
* Get the subscription associated with this subscriber.
*
* @return
* A PuSHSubscriptionInterface object if a subscription exist, NULL
* otherwise.
*/
public function subscription() {
return call_user_func(array(
$this->subscription_class,
'load',
), $this->domain, $this->subscriber_id);
}
/**
* Determine whether this subscriber is successfully subscribed or not.
*/
public function subscribed() {
if ($sub = $this
->subscription()) {
if ($sub->status == 'subscribed') {
return TRUE;
}
}
return FALSE;
}
/**
* Helper for messaging.
*/
protected function msg($msg, $level = 'status') {
$this->env
->msg($msg, $level);
}
/**
* Helper for logging.
*/
protected function log($msg, $level = 'status') {
$this->env
->log("{$this->domain}:{$this->subscriber_id}\t{$msg}", $level);
}
}
/**
* Implement to provide a storage backend for subscriptions.
*
* Variables passed in to the constructor must be accessible as public class
* variables.
*/
interface PuSHSubscriptionInterface {
/**
* @param $domain
* A string that defines the domain in which the subscriber_id is unique.
* @param $subscriber_id
* A unique numeric subscriber id.
* @param $hub
* The URL of the hub endpoint.
* @param $topic
* The topic to subscribe to.
* @param $secret
* A secret key used for message authentication.
* @param $status
* The status of the subscription.
* 'subscribe' - subscribing to a feed.
* 'unsubscribe' - unsubscribing from a feed.
* 'subscribed' - subscribed.
* 'unsubscribed' - unsubscribed.
* 'subscribe failed' - subscribe request failed.
* 'unsubscribe failed' - unsubscribe request failed.
* @param $post_fields
* An array of the fields posted to the hub.
*/
public function __construct($domain, $subscriber_id, $hub, $topic, $secret, $status = '', $post_fields = '');
/**
* Save a subscription.
*/
public function save();
/**
* Load a subscription.
*
* @return
* A PuSHSubscriptionInterface object if a subscription exist, NULL
* otherwise.
*/
public static function load($domain, $subscriber_id);
/**
* Delete a subscription.
*/
public function delete();
}
/**
* Implement to provide environmental functionality like user messages and
* logging.
*/
interface PuSHSubscriberEnvironmentInterface {
/**
* A message to be displayed to the user on the current page load.
*
* @param $msg
* A string that is the message to be displayed.
* @param $level
* A string that is either 'status', 'warning' or 'error'.
*/
public function msg($msg, $level = 'status');
/**
* A log message to be logged to the database or the file system.
*
* @param $msg
* A string that is the message to be displayed.
* @param $level
* A string that is either 'status', 'warning' or 'error'.
*/
public function log($msg, $level = 'status');
}Classes
Name |
Description |
|---|---|
| PuSHSubscriber | PubSubHubbub subscriber. |
Interfaces
|
Name |
Description |
|---|---|
| PuSHSubscriberEnvironmentInterface | Implement to provide environmental functionality like user messages and logging. |
| PuSHSubscriptionInterface | Implement to provide a storage backend for subscriptions. |